How to Get Low Stock Alerts in Shopify (and Set the Right Threshold)

1. Set up a low stock email with Shopify Flow

Flow is Shopify’s free automation app. Shopify says (opens in a new tab) it’s available on the Basic, Grow, Advanced and Plus plans. Install it from the Shopify App Store if it isn’t in your admin yet, then:

1. Open Flow, go to Templates and search for “inventory is low”. Choose the template that emails you when product variant inventory is low.
2. The workflow starts with the Inventory quantity changed trigger. It runs every time a variant’s stock changes.
3. In the condition, set the number of units that counts as low. Keep the second check on the quantity before the change. It makes the email go out once, when stock crosses your number, instead of after every sale below it.
4. In the Send internal email action, enter your address. Separate several addresses with commas.
5. Turn the workflow on.

Shopify’s Flow workflow examples (opens in a new tab) walk through the same low stock workflow, including the before-and-after check.

2. Where a single threshold falls short

The workflow works, but it treats every product the same way:

• One number for everything. A product that sells one a week and a best seller that sells five a day both alert at the same level. The slow one alerts weeks too early, the best seller too late.
• It ignores delivery time. Ten units left is plenty if your supplier delivers in two days and far too few if they take three weeks.
• One email per variant. Each variant that crosses the line sends its own email. On a busy day that’s a stack of messages, not one list to order from.
• It needs a plan with Flow. Shopify doesn’t list Flow on the Starter plan.

You can give groups of products their own number in Flow, for example one condition per product tag. Every new product then needs the right tag, and you keep the numbers up to date by hand.

3. Set a threshold that matches each product

The question an alert should answer is: will this run out before a new delivery can arrive? That gives you a simple formula:

A product that sells 3 a day from a supplier that takes 7 days to deliver should alert at 21. If you order the day the alert arrives, the delivery lands as the last unit sells. Add a few days of buffer if the supplier is sometimes late, or if you don’t place orders every day.

For daily sales, take the units sold over the last four weeks and divide by 28. Be careful with products that sold out during those weeks. The days with nothing to sell pull the average down, so your best sellers look slower than they are. Our guide to days of inventory remaining shows how to correct for that.

When the alert arrives, it tells you to order, not how much. Our reorder guide covers the quantity.

Alerts that work out the threshold for you

Keeping a separate number for every product is the spreadsheet job most stores never get round to.

Efficiencia’s stock alerts use the same idea, product by product. Each product’s rate comes from its own recent sales, leaving out the days it was sold out, and its lead time comes from its supplier. Stock already on order counts. You get an email when a product sells out, or when its stock won’t last until an order can arrive. Alerts are batched into one email at most every 30 minutes, and each product is mentioned once until it’s back in stock.

A morning email, daily or on Mondays only, lists the suppliers to reorder from and the products that run out first. Both emails link to Today, where each supplier’s order is ready to review.

Efficiencia is still in development. If you’d like to try it on your store, join early access.